diff --git a/.github_changelog_generator b/.github_changelog_generator
deleted file mode 100644
index 4549a7f79..000000000
--- a/.github_changelog_generator
+++ /dev/null
@@ -1,10 +0,0 @@
-user=zammad
-project=zammad
-output=CHANGELOG.md
-since-tag=1.0.0
-bug-labels=bug,minor bug,security
-enhancement-labels=enhancement,feature,feature backlog
-issues-wo-labels=false
-include-labels=security,trigger,UX/UI,admin area,API,browser,bug,channel,chat,email filter,enhancement,feature,feature backlog,import,minor bug,notification,email filter,ticket templates,
-issue-line-labels=enhancement,feature,feature backlog,bug,minor bug,notification,reporting,security,ticket templates,translation,trigger,UX/UI
-exclude-tags=9.0.1,0.9.1,v0.1.8,v0.1.7,unittests_passed
diff --git a/Gemfile b/Gemfile
index f89de9b22..cca5e1229 100644
--- a/Gemfile
+++ b/Gemfile
@@ -199,9 +199,6 @@ group :development, :test do
   gem 'rubocop-rails'
   gem 'rubocop-rspec'
 
-  # changelog generation
-  gem 'github_changelog_generator'
-
   # generate random test data
   gem 'factory_bot_rails'
   gem 'faker'
diff --git a/Gemfile.lock b/Gemfile.lock
index 0638fa285..63a904ba0 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -96,24 +96,6 @@ GEM
       ffi (~> 1.14)
       ffi-compiler (~> 1.0)
     ast (2.4.2)
-    async (1.30.1)
-      console (~> 1.10)
-      nio4r (~> 2.3)
-      timers (~> 4.1)
-    async-http (0.56.5)
-      async (>= 1.25)
-      async-io (>= 1.28)
-      async-pool (>= 0.2)
-      protocol-http (~> 0.22.0)
-      protocol-http1 (~> 0.14.0)
-      protocol-http2 (~> 0.14.0)
-    async-http-faraday (0.11.0)
-      async-http (~> 0.42)
-      faraday
-    async-io (1.32.2)
-      async
-    async-pool (0.3.9)
-      async (>= 1.25)
     autoprefixer-rails (10.4.2.0)
       execjs (~> 2)
     binding_of_caller (1.0.0)
@@ -157,8 +139,6 @@ GEM
     composite_primary_keys (12.0.10)
       activerecord (~> 6.0.0)
     concurrent-ruby (1.1.9)
-    console (1.13.1)
-      fiber-local
     crack (0.4.5)
       rexml
     crass (1.0.6)
@@ -214,8 +194,6 @@ GEM
     faraday-em_http (1.0.0)
     faraday-em_synchrony (1.0.0)
     faraday-excon (1.1.0)
-    faraday-http-cache (2.2.0)
-      faraday (>= 0.8)
     faraday-httpclient (1.0.1)
     faraday-multipart (1.0.3)
       multipart-post (>= 1.2, < 3)
@@ -230,17 +208,7 @@ GEM
     ffi-compiler (1.0.1)
       ffi (>= 1.0.0)
       rake
-    fiber-local (1.0.0)
     formatador (0.3.0)
-    github_changelog_generator (1.16.4)
-      activesupport
-      async (>= 1.25.0)
-      async-http-faraday
-      faraday-http-cache
-      multi_json
-      octokit (~> 4.6)
-      rainbow (>= 2.2.1)
-      rake (>= 10.0)
     gli (2.20.1)
     globalid (1.0.0)
       activesupport (>= 5.0)
@@ -351,9 +319,6 @@ GEM
       multi_json (~> 1.3)
       multi_xml (~> 0.5)
       rack (>= 1.2, < 3)
-    octokit (4.21.0)
-      faraday (>= 0.9)
-      sawyer (~> 0.8.0, >= 0.5.3)
     omniauth (1.9.1)
       hashie (>= 3.4.6)
       rack (>= 1.6.2, < 3)
@@ -403,13 +368,6 @@ GEM
       ast (~> 2.4.1)
     pg (0.21.0)
     power_assert (2.0.1)
-    protocol-hpack (1.4.2)
-    protocol-http (0.22.5)
-    protocol-http1 (0.14.2)
-      protocol-http (~> 0.22)
-    protocol-http2 (0.14.2)
-      protocol-hpack (~> 1.4)
-      protocol-http (~> 0.18)
     pry (0.14.1)
       coderay (~> 1.1)
       method_source (~> 1.0)
@@ -542,9 +500,6 @@ GEM
       sprockets (> 3.0)
       sprockets-rails
       tilt
-    sawyer (0.8.2)
-      addressable (>= 2.3.5)
-      faraday (> 0.8, < 2.0)
     selenium-webdriver (4.1.0)
       childprocess (>= 0.5, < 5.0)
       rexml (~> 3.2, >= 3.2.5)
@@ -579,7 +534,6 @@ GEM
     thor (1.2.1)
     thread_safe (0.3.6)
     tilt (2.0.10)
-    timers (4.3.3)
     twilio-ruby (5.63.1)
       faraday (>= 0.9, < 2.0)
       jwt (>= 1.5, <= 2.5)
@@ -671,7 +625,6 @@ DEPENDENCIES
   execjs
   factory_bot_rails
   faker
-  github_changelog_generator
   gmail_xoauth
   guard
   guard-livereload
diff --git a/script/build/cleanup.sh b/script/build/cleanup.sh
index 32ae6a031..d4e0371b9 100755
--- a/script/build/cleanup.sh
+++ b/script/build/cleanup.sh
@@ -26,4 +26,3 @@ rm .overcommit.yml
 
 # misc
 rm .codeclimate.yml
-rm .github_changelog_generator